We've known it was coming for some time now, but T-Mobile just sent out a press release including details regarding their plans for a WiFi Calling application for their Android phones. The new T-Mobile myTouch will launch later this year with the feature, and the Motorola Defy will be receiving it as well. Additionally, the T-Mobile G2 should be getting it in the coming months, along with the LG Optimus and possibly the Motorola Charm.